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<html lang="en">

<head>
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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

    <div id="app">
        <div ref="box">
            我是dom结构
            <input ref="ipt" type="text">

            <audio src="" controls></audio>
        </div>
    </div>

    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
    <script>
        let vm = new Vue({
            // 元素
            el: "#app",
            data: {
                msg: "标题"
            },
            created() {
                console.log(this.$refs.box)
            },
            // 
            mounted() {
                // this.$refs.box.innerHTML = '123'
                this.$refs.ipt.focus()
            }
        })
    </script>
</body>

</html>